Serial data transmission typically involves the encoding of the data to be transmitted in an appropriate code for the transmission medium and the framing of the encoded data into blocks of serial data for transmission. The purpose of framing the data is to provide identification codes and timing signals that facilitate the detection of the beginning and end of data and the synchronism necessary to permit decoding of the received data. In those applications where the signal to noise ratio is low, special efforts must be undertaken to insure that the integrity of the transmitted data is maintained. To this end, sophisticated error detecting and correcting codes have been devised. These codes require the addition of bits to the framed data code that is to be transmitted. Thus, a large portion of the transmitted frame is composed of frame synchronising codes, clock timing pulses and error detection and correction bits. In other words, the overhead required to synchronously or asynchronously transmit serial data is a substantial portion of the frame that transmits the data. Even so, in particularly noisy environments, redundant transmission is often resorted to in order to minimize data errors. Whether the environment is especially noisy or is less hostile to the accurate transmission and/or recording of data, it is generally the goal of the communications engineer to decrease the overhead required to transmit data.